"I have all the prerequisites..." but java.version of 1.5 is not on that
list. Okay, so let's go with the stock answer when people ask about Java
1.5 ... "it should work" ... and see what else it might be.

How did you install the pre-reqs? Download and unzip? Or update manager?
If the former, did you try starting -clean??

M2050929-0840 is Eclipse 3.1.1, as I recall. What version of TPTP did
you get? 4.1.0? 4.1.0.1??
--
RDS